What you need to know about blood pressure during pregnancy

by Kaiser Permanente |
Pregnant person checking blood pressure at home during video visit.

When your clinician checks your blood pressure, they’re measuring the force your blood creates when it flows through your arteries. High blood pressure (hypertension) means that the force of blood against your artery walls is too strong. High blood pressure usually does not cause symptoms.

During pregnancy, severe or uncontrolled high blood pressure can cause problems for you and your baby. Hypertension can also increase your risk of stroke, heart attack, or other problems. That’s why it’s important to watch it closely while you’re pregnant and after delivery. To help you know what to look for, here’s an overview of how high blood pressure can affect your pregnancy.

The risks of high blood pressure

Typically, your blood pressure is lower than usual during your second trimester. It usually comes back up to normal by the time you’re ready to deliver your baby. This is why high blood pressure is often not diagnosed until the third trimester. High blood pressure during pregnancy can affect the amount of oxygen and nutrients your baby receives. This can cause growth problems or even stillbirth. It can also cause your placenta to separate too early. This is called placental abruption and can be a severe emergency.

Some people have high blood pressure before they become pregnant — this is called chronic hypertension. Others develop high blood pressure while they’re pregnant, a condition called gestational hypertension. People with any type of high blood pressure during pregnancy are at higher risk of developing preeclampsia, a condition that involves other organs and can be dangerous both for moms and babies. Preeclampsia can turn into eclampsia, which causes seizures.

Diagnosing and treating high blood pressure in pregnancy

For most pregnant people, high blood pressure doesn’t cause any symptoms and is only discovered during a prenatal office visit. Getting your blood pressure checked regularly is one of the reasons why it’s important to attend all your prenatal visits.

If you have high blood pressure while you’re pregnant, your clinician will want to check it more often. This can be done at in-person visits or remotely with a blood pressure cuff that you use at home. They will also monitor your baby more closely. You may need to take medication to lower your blood pressure.

To lower your risk of developing high blood pressure, try:

  • Eating a healthy diet
  • Getting regular exercise
  • Gaining a healthy amount of weight during pregnancy
  • Quitting smoking

Your clinician may recommend that you take low dose aspirin daily if you have chronic hypertension or other risk factors for preeclampsia.

If high blood pressure affects the health of you or your baby, your clinician might decide to deliver the baby early. High blood pressure usually goes back to normal after the baby is born, but it’s important to keep all your postpartum appointments to be sure this happens. Some women can even develop high blood pressure during labor or right after delivery.

Understanding preeclampsia

Preeclampsia is serious. It can reduce blood flow to your placenta, or it may narrow the blood vessels in your uterus or other organs. Both can lead to problems for you and your baby. This condition is most common in the third trimester, but it can begin earlier or even after delivery.

Unlike chronic hypertension and gestational hypertension, preeclampsia can cause symptoms.

It’s important to know the warning signs so you can get help. Let your care team know right away if you have:

  • Blurred vision, spots in front of your eyes, or other problems seeing
  • A severe headache that doesn’t go away with acetaminophen, which is found in pain relievers such as Tylenol
  • Pain in your upper abdomen that won’t go away
  • Swelling in your face or hands
  • Decreased fetal activity

When to contact your care team

If you have high blood pressure during pregnancy, knowing when to get help is critical.

Tell the people around you to call 911 immediately if you lose consciousness or have a seizure. If you’re alone, call 911 as soon as you’re able to.

Seek immediate medical care if you have:

  • Any symptoms of preeclampsia
  • New nausea or vomiting
  • Pain in your pelvis or abdomen or any vaginal bleeding
  • Very high blood pressure — 160/110 or higher
  • Blood pressure that is higher than the goal your clinician set for you
  • Chest pain or new onset of shortness of breath

Kaiser Permanente does not endorse the medications or products mentioned. Any trade names listed are for easy identification only.

This article has been created by a national group of Kaiser Permanente ob-gyns, certified nurse-midwives, pediatricians, lactation consultants and other specialists who came together to provide you with the best pregnancy, birth, postpartum, and newborn information.

Some of the content is used and adapted with permission of The Permanente Medical Group.